Air Plants (Tillandsias), as the name implies, get their nutrients and water from the air. This means they do not need to be planted in soil; instead, they commonly grow while attached to other plants or by moving around the desert, like nomads. These soil-less oddities come in many shapes and sizes. Related to Orchids, there are over 550 species in several different parts of the world, including here here here and here. Propagation is possible with seeds, however, it is more common for air plants to have offshoots, called pups. For the most part, Air Plants are easy to care for as house plants.
: Stein, Les. "8 Air Plants Facts You Might Not of Known." Plantstr. February 7, 2015. Accessed February 18, 2016. http://www.plantstr.net/blogs/news/16906997-8-air-plants-facts-you-might-not-of-known.
: Brown, Adrienne. "The Magic of Air Plants." Canadian Gardening. Accessed February 18, 2016. http://www.canadiangardening.com/plants/indoor-plants/the-magic-of-air-plants/a/46085.
: Richards, Julie. "How to Propagate Tillandsia." Home Guides. Accessed February 18, 2016. http://homeguides.sfgate.com/propagate-tillandsia-63613.html.